Archimedes Tech SPAC Partners III ARCIU Institutional Ownership

NASDAQ ARCIU

$10.14 +0.01 (+0.10%)

At close: Nov 5, 2026 · 4:00 PM EST

Institutions by Trading Activity

15 Institutions

Increased 7 46.7%

Unchanged 7 46.7%

Reduced 1 6.7%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

—

not available

Shares Held by Institutions

4.63Mn

of 0 outstanding

▼-49.17% QoQ

Shares Outstanding

Institutional Investors

filed 13F for Jun 2026

▼-14 vs prior quarter

Net Shares Added (QoQ)

-4.47Mn

distributed since last quarter

Value of Holdings

$46.90Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 16, 2026

Archimedes Tech SPAC Partners III Co. (NASDAQ:ARCIU) appeared in the 13F filings of 15 institutional investors for the quarter ended June 30, 2026.

Total holdings of Archimedes Tech SPAC Partners III shares fell 49.17% compared with Q1 2026.
Of these 15 holders, 7 added to their positions, 1 reduced its stake and 7 left their positions unchanged.
Institutional investors held 4.63Mn shares of Archimedes Tech SPAC Partners III in total at the end of Q2 2026, down 4.47Mn from the prior quarter.
As of June 30, 2026, LMR Partners LLP held the largest stake in Archimedes Tech SPAC Partners III with 1.25Mn shares.
The biggest increases in ARCIU positions during Q2 2026 came from Toronto Dominion Bank (+396.22K shares), Clear Street Group Inc. (+24.19K shares), Lineage Point Capital LP (+13.78K shares), Aristeia Capital, L.L.C. (+989 shares) and Tuttle Capital Management, LLC (+769 shares).
The holder that trimmed the most shares of Archimedes Tech SPAC Partners III in Q2 2026 while keeping a position was Millennium Management LLC (-170.26K shares).
Per Business Quant, the top 10 investors in ARCIU for the quarter ended June 30, 2026 were LMR Partners LLP (1.25Mn shares), Tudor Investment Corp (650K shares), Toronto Dominion Bank (646.22K shares), Omers Administration Corp (480K shares), Aristeia Capital, L.L.C. (400.78K shares), Lineage Point Capital LP (288.78K shares), BlueCrest Capital Management Ltd (275K shares), Millennium Management LLC (179.74K shares), Qube Research & Technologies Ltd (150K shares) and Calamos Advisors LLC (124K shares).

Form 13F Holdings

15 Institutional Holders

Report period 30 Jun, 2026

Total shares held 4.63Mn

Of outstanding —

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	LMR Partners LLP	0001578621	1,250,000	—	0	0.00%	$12.74Mn
2	TUDOR INVESTMENT CORP ET AL	0000923093	650,000	—	0	0.00%	$6.62Mn
3	Toronto Dominion Bank	0000947263	646,217	—	▲396,217	+158.49%	$6.59Mn
4	OMERS ADMINISTRATION Corp	0001053321	480,000	—	0	0.00%	$4.89Mn
5	ARISTEIA CAPITAL, L.L.C.	0001080171	400,779	—	▲989	+0.25%	$4.08Mn
6	Lineage Point Capital LP	0002093311	288,776	—	▲13,776	+5.01%	$3.01Mn
7	BlueCrest Capital Management Ltd	0001610880	275,000	—	0	0.00%	$2.82Mn
8	MILLENNIUM MANAGEMENT LLC	0001273087	179,743	—	▼170,257	-48.64%	$1.83Mn
9	Qube Research & Technologies Ltd	0001729829	150,000	—	0	0.00%	$1.54Mn
10	Calamos Advisors LLC	0001316507	124,000	—	0	0.00%	$1.29Mn
11	Westchester Capital Management, LLC	0001512805	100,000	—	0	0.00%	$1.02Mn
12	Clear Street Group Inc.	0001881567	34,256	—	▲24,194	+240.45%	$349.07K
13	HRT FINANCIAL LP	0001475597	25,000	—	▲4	+0.02%	$256
14	Tuttle Capital Management, LLC	0001581641	10,769	—	▲769	+7.69%	$109.41K
15	GLAZER CAPITAL, LLC	0001076809	10,523	—	▲10,523	0.00%	$110